New inexpensive materials bring cheap hydrogen fuel closer to reality

Washington, Feb. 23: Researchers have combined cheap, oxide-based materials to split water into hydrogen and oxygen gases using solar energy with a solar-to-hydrogen conversion efficiency of 1.7 percent, the highest reported for any oxide-based photoelectrode system.

Kyoung-Shin Choi, a chemistry professor at the University of Wisconsin-Madison and postdoctoral researcher Tae Woo Kim created solar cells from bismuth vanadate using electrodeposition – the same process employed to make gold-plated jewelry or surface-coat car bodies – to boost the compound’s surface area to a remarkable 32 square meters for each gram.

Choi said that without fancy equipment, high temperature or high pressure, we made a nanoporous semiconductor of very tiny particles that have a high surface area, asserting that more surface area means more contact area with water, and, therefore, more efficient water splitting.

Bismuth vanadate needs a hand in speeding the reaction that produces fuel, and that’s where the paired catalysts come in.hoi and Kim exploited a pair of cheap and somewhat flawed catalysts – iron oxide and nickel oxide – by stacking them on the bismuth vanadate to take advantage of their relative strengths.